Almost half of the reef's coral has vanished over the past three decades, thanks to warming ocean temperatures, invasive species and coastal development.

This year, the reef suffered the worst coral bleaching in recorded history. One study estimated over 90 percent of the reef has been affected.

The Australian government thought the reef's dire state would drive tourists away, but it's done the opposite. That's great news for the multibillion-dollar tourism industry, but it could be bad news for the reef itself.

This phenomenon is called last-chance tourism, and it happens all the time at vanishing destinations, like the Maldives and Galapagos Islands.

Researchers fear it could make the reef's plight even worse.

One of the study's authors wrote in The Conversation, "There's a vicious cycle at play here: tourists travel to see a destination before it disappears, but in so doing they contribute to its demise, either directly through on-site pressures or ... through greenhouse gas emissions."

But a reef scientist told Motherboard the impacts of tourism are actually "overwhelmingly positive."

"The greater the value of Great Barrier Reef tourism, the easier it is to justify government investment in reef management," said reef scientist Peter Mumby.

And the reef might already be seeing those positive effects. A new video from early September showed at least part of the reef has almost fully recovered from coral bleaching.

It has been well-documented that the conditions of Rio’s water prior to the Olympics were not ideal. While the country was unable to do anything about it, a Florida man said he's going to try.

Brad Funk, of Fort Lauderdale, is in Rio primarily to support his girlfriend, windsurfer Bryony Shaw from Great Britain. But he's using the rest of his time to try and help clean up the massive heaps of trash, debris and fecal matter polluting the water in the city, the Bradenton Herald reported.

>> Read more trending stories

"No Olympic medal should be won or lost because of trash in the water," he said. "Rio is my favorite place in the world to sail, and it would be a shame if the regatta was compromised by pollution."

Funk, who has missed out on making the U.S. Olympic sailing team in three attempts, said he has scooped around 800 pounds of trash out of the water.

"If I helped one person, I’ll be happy that I was useful to the Olympics," he told the Herald. "This is our playground. We all live on a water planet. We’ve got to pitch in and save the environment before it’s too late."

Funk said he spent thousands of his own dollars to hire a fishing boat captain who allows him to fill his boat with garbage bags of trash. "I'd give anything to sail in the Olympics," he said. "I hope people will see how beautiful this bay can be."

An Associated Press report found "disease-causing viral levels 1.7 million times higher than normal" in areas of the bay where Funk is sailing, the Herald added. Olympic officials maintain that it's safe for competition.

Just in time for summer vacations and halfway points for paid time off, Travel + Leisure magazine has released its World's Best Awards, multiple lists identifying the best islands in the world, the best cities in the world, the best domestic airports and the best hotels in the U.S., among other desirable destinations and attractions.

Here are a few places to add to your bucket list, according to Travel + Leisure:

Top 10 cities around the world

10. Cape Town, South Africa

9. Savannah, Georgia

8. Barcelona, Spain

7. New Orleans, Louisiana

6. Kyoto, Japan

5. Luang Prabang, Laos

4. Florence, Italy

3. San Miguel de Allende, Mexico

2. Chiang Mai, Thailand

1. Charleston, South Carolina

"Charleston is a remarkably dynamic place, so it's no surprise that it has achieved its highest ranking ever in our survey as this year's best city in the world," said Nathan Lump, the magazine's editor. "The city has managed to preserve all the qualities for which it is widely known -- a prime coastal setting, historic architecture, friendly locals -- while also nurturing a creative culture that is making it one of the most notable destinations for those who seek out interesting restaurants, bars and shops."

"What truly makes a statement on the line’s twin 930-passenger ships, Viking Star and Viking Sea, is the Scandinavian aesthetic, which translates to airy cabins (all of which have full-size balconies) and public spaces," Travel + Leisure's Jacqueline Gifford wrote. "Wi-Fi is free to all guests, no matter their cabin class, and there is no surcharge to dine outside the main restaurant in places like The Chef’s Table, which serves a five-course tasting menu."

But the staples are there too like a state-the-art step into Pirates of the Caribbean where the likes of Jack Sparrow, sorry, CAPTAIN Jack Sparrow and Davy Jones go from a skeletal crew to "living" swashbucklers.

Disney chief executive Bob Iger said this project is 17 years in the making for him as he lobbied with Chinese officials to make the park happen.

Disney wound up with only a 43 percent stake in the park, with a Chinese state-owned company holding the rest.

They company also has operating agreements for its parks in other parts of the world.

Tokyo Disneyland, which was the first Disney park built outside the U.S., opened in 1983. In 2001, DisneySea opened. Both are owned by Japan's Oriental Land Company, The Associated Press reported.

Disneyland Paris, originally called EuroDisney, opened in 1992. It is still operated under a publicly traded company called Euro Disney.

Hong Kong Disney opened in 2005. Hong Kong's government owns 53 percent of that park. It didn't turn a profit until 2012 and has since gone back into debt. An Iron Man expansion is set to open this year, The AP reported.

But there's still a lot to be had from Disney's investment there. The Guardian reports 330 million people live within a three-hour drive of the park, and an estimated 10 million people will visit each year. But some analysts say that number could be as high as 50 million.

The opening of the new park has been in a trial run since May, and Shanghai city officials issued a guide book for locals after they saw what officials called "uncivilized behaviors" inside the park, CNN reported.

Among the behavior that is frowned upon: littering, cutting line, damaging the landscape and vandalism.

When a nearby metro station opened in April, visitors went to the property and reportedly caused damage to the area outside of the park's gates, CNN reported.

And there's the added benefit of the park increasing interest for Disney's already monster-sized movie franchises.

Another highlight of the new park is the premier of a new "Soarin' Around the World" film. The film is having its world-wide debut during Shanghai's grand opening, but will appear in Disney's California Adventure park in California and Epcot at Walt Disney World in Florida starting Friday, which just happens to be exactly one month before the 61st anniversary of Walt Disney's original theme park, Disneyland.

Also opening next week, the long-awaited ride that features Elsa, Ana and Olaf. Frozen Ever After is scheduled to open its doors on June 21 in the Norway section of the park, replacing the Maelstrom ride.

And while it is a time of celebration for some aspects of the company, Disney has taken a public relations hit stateside.

A 2-year-old toddler was attacked and killed by an alligator this week at the Orlando resort's flagship hotel, The Grand Floridian.

The body of Lane Graves was found Wednesday. He had been playing in shallow water at the hotel Tuesday night. There are "no swimming" signs at the hotel's beach, but no warnings of alligators.

The department's spokesperson said the alert is a renewal of a travel notice issued after the March terrorist attacks in Brussels. He said the department typically waits to renew an alert when it's about to expire but the department issued it early since the summer travel season is starting.

"I'm not aware of any specific, credible terrorist threat around these events or in any particular place in Europe. This alert was issued, as they always are, based on a cumulation of information," U.S. State Department Spokesperson John Kirby explained.

The State Department said American tourists should be aware of their surroundings and avoid crowded places. The travel alert expires Aug. 31.

In what will be the company's first-ever underwater bedroom, guests can sleep 32 feet below the surface in a room defined by a cylindrical glass wall designed to give a 360-degree view of aquatic life.

Contestants can win a one-night stay in the underwater oasis by entering Airbnb’s limited-time contest. A round trip to Paris (economy class tickets), a private visit and tour of the Aquarium de Paris, a private dinner for two in the aquarium and breakfast the morning after the stay are also included in the winnings. Each winner is allowed one guest.

>>This treehouse is Airbnb's most desired rental property in the world

Interested travelers must write about a unique reason they should be afforded the opportunity to sleep with the fierce animals in 50-550 words in order to win the underwater stay for two one night between April 11 and April 13. Entries will be evaluated for "originality," "creativity" and "spirit of the submission."

The special offering was designed to teach people more about sharks, which Airbnb and Aquarium de Paris believe are the most misunderstood animals in the world.

"Avoid seeing Jaws before your sleepover," Airbnb jokes in a section of the contest rules.

Three contest winners will be selected on April 9 and announced on social media.

The World Happiness Report for 2016 ranks 156 countries by their happiness levels, using data collected from a Gallup poll to measure economical, psychological, health and public policy factors, among others.

The report, released just days ahead of UN World Happiness Day on Sunday, ranks the top 10 happiest countries as follows:

1. Denmark

2. Switzerland

3. Iceland

4. Norway

5. Finland

6. Canada

7. Netherlands

8. New Zealand

9. Australia

10. Sweden

Denmark previously topped the list in 2012 and 2013.

The report ranks Burundi as the least happy nation. Data collected found that inequality among people was strongly associated with unhappiness.

For some, this will be the second time in their lifetime that the falls have dried.

In 1969 researchers stopped the flow of water to study the effects of erosion and buildup of rock at the base of the falls. That year, people traveled from all over the world to see the landmark de-watered.

According to The Buffalo News, the New York State parks system wants to halt the water on the American side of the falls to replace two 115-year-old stone arch bridges that allow pedestrians, park vehicles and utilities access to Goat Island. Officials have said the concrete bridges, built in 1901, are deteriorating. A renovation would improve safety and the overall look of the popular site.

In 2004, the concrete arch bridges were closed and temporary truss bridges were put in place for parkgoers to cross over the rapids. Ten years later, the temporary bridges, which block views of the falls and are aesthetically unappealing for visitors, are still in place.

Officials now want to replace the two stone arch bridges, a project that could take five to nine months and would cost between $21.6 million and $37.3 million, The Buffalo News reported.

"The biggest problem is coming up with the money to do this," said Niagara Falls historian Tom Yots. "These beautiful bridge designs go back to the beginning of the 20th century."

The park system's proposal will be presented at a public hearing Wednesday at the Niagara Falls Conference Center.

If approved, a cofferdam would be imposed to stop water from flowing on the American side and redirect it to flow down the Canadian side. About 85 percent of the Niagara River flows over Horseshoe Falls in Ontario, and 15 percent flows over the American Falls in New York.